A gas turbine engine includes a fan section that drives air along a bypass flowpath while a compressor section drives air along a core flowpath for compression and communication into a combustor section then expansion through a turbine section.
One example fan blade includes a cover attached to a blade body. An inner surface of the blade body of the fan blade includes cavities. A piece of low density filler is placed into a corresponding cavity in the blade body. An exposed surface of the low density filler must conform closely to a surface of the blade body to enable a robust bond joint to a mating surface of the cover. Due to variation in the manufacturing processes, currently an operator manually applies pressure to any high spots in the low density filler, and then taps the high spots of the low density filler with an instrument so that an upper surface of the low density filler is approximately flush with the inner surface of the blade body to create a smooth surface. A drawback to this method is that it is labor intensive for an operator to manually tap each piece of low density filler.